P-233: Study of Chromosomal Alterations and Polymorphisms of MTHFR, Factor V and Prothrombin Genes in Patients with Recurrent Miscarriage Referred to Royan Institute

Background: Recurrent miscarriage (RM) is defined as two or more consecutive pregnancy losses before 20 weeks of gestation as an important clinical problem, with an incidence of 1-3% among couples wishing to have children. There are several factors in the etiology of recurrent miscarriage. One of the main genetic causes which involve in the pathogenesis of RM is balanced chromosomal rearrangements in one or both of partners. In 4-8% of couples with RM, at least one of the partners has chromosomal abnormality. Next to chromosomal abnormalities, thrombophilia was identified as a major cause of RM, with a rate of up to 40%, especially in the first half of pregnancy. Materials and Methods: The patient groups included 1100 Iranian couples (2200 individuals) referred to Royan Institute between 2004 and 2013. Karyotyping was performed using standard cytogenetic techniques. Besides, thrombotic gene polymorphisms were studied in 128 women who had a normal karyotype.The results were compared with 70 healthy women as control group. Results: Abnormal karyotypes were found in 124 people, 83 women (3.77%) and 41 men (1.86%). The frequency of FV Leiden, ProthrombinG20210A, MTHFRC677T and MTHFRA1298C mutations in patients were 10.93, 4.68, 43.75 and 60.15%, respectively. These frequencies in control group were 2.85, 2.85, 34.28 and 5.71% respectively. Conclusion: Sex chromosome mosaicism is the most commonly detected chromosomal abnormality in couples with RM who are candidates for offering PGD. Patients with combined thrombophilic mutations are at higher risk of RM than women without these mutations. The most important issue with hereditary thrombophilia's is the prevention of maternal thrombosis.